I have a 1986 Mercedes-Benz 300E with keyless entry (no door locks so I cant open the doors manually/with the ignition key) and the alarm remote isn't opening the vehicle. I have 2 keyless entry alarm remotes where the batteries are both ok (the red light comes on whenever I press the button), but unfortunately it still won't open the car.

I think that the keyless entry alarm system may have a faulty wire, a problem with the transmitter and/or controller chip, or it needs to be reprogrammed. I also read that it may be the IFZ (infra red system) or maybe the ECU (control unit). Any advice would be greatly appreciated.

Thank you for your time.